Aircraft noise pollution is a significant environmental problem for communities near airports. A large portion of the noise produced by an aircraft during the approach and landing phase of a flight is generated by the airframe. Such approach noise is generally the result of air flowing over and around the airframe components such as over the landing gear and over devices that may be deployed from the aircraft wings. Such devices may include flaps mounted to the trailing edges of the wings and conventional slats or flaps (e.g., Krueger flaps) mounted to the wing leading edges and which may be deployed or deflected downwardly from the wings during approach and landing. By deploying the flaps or slats, airflow may be maintained over the wings at high angles of attack, which may allow for a reduction in the approach and landing speed of the aircraft and/or an increase in the descent angle of the aircraft.
The noise generated by conventional leading edge devices such as conventional slats or flaps may be attributed to turbulence created by sharp edges of the deployed devices. The noise may also be attributed to turbulence generated by air flowing through gaps in the deployed devices or gaps between the wings and the deployed devices. Furthermore, turbulence associated with conventional slats and flaps may cause vibration and flutter in the slats or flaps, which, over time, may have an undesirable effect on the actuating mechanisms for deploying the flaps or slats.
As can be seen, there exists a need in the art for a leading edge device of an airfoil, such as an aircraft wing, which generates a reduced amount of airframe noise when the leading edge device is deployed. In this regard, there exists a need in the art for a leading edge device for an airfoil that generates a reduced amount of turbulence when the leading edge device is deployed.